Actuator and Sensor Assembly

ABSTRACT

An actuator and sensor assembly comprising respective sensor and actuator housings defining an interior chamber. Clips on the sensor housing engage the actuator housing for coupling the sensor and actuator housings together. The sensor housing includes a wall defining a pocket. A connector with a sensor couples to the sensor housing in a relationship wherein the sensor extends into the sensor housing pocket. A movable piston is located in the interior chamber and a tube thereon defines a receptacle for a magnet located adjacent the pocket. The piston is seated on a flexible diaphragm. An actuator shaft includes one end coupled to the piston and an opposite end coupled to a movable object. A plurality of pins in the actuator housing mount the assembly to a support bracket. The sensor senses changes in the magnetic field in response to changes in the position of the magnet relative to the sensor.

CROSS REFERENCE TO RELATED AND CO-PENDING APPLICATIONS

This application is a continuation application which claims the benefitof the filing date of co-pending U.S. patent application Ser. No.12/962,773 filed on Dec. 8, 2010 which is a continuation-in-partapplication of U.S. patent application Ser. No. 12/315,332 filed on Dec.2, 2008 now U.S. Pat. No. 8,395,374 issued on Mar. 12, 2013 and U.S.patent application Ser. No. 12/592,170 filed on Nov. 20, 2009 now U.S.Pat. No. 8,400,142 issued on Mar. 19, 2013, the contents of which arealso entirely incorporated herein by reference as are all referencescited therein.

This application also claims the benefit of the filing date anddisclosure of U.S. Provisional Patent Application Ser. No. 61/284,027filed on Dec. 9, 2009; U.S. Provisional Patent Application Ser. No.61/284,028 filed on Dec. 9, 2009; and U.S. Provisional PatentApplication Ser. No. 61/340,813 filed on Mar. 22, 2010, the contents ofwhich are entirely incorporated herein by reference as are allreferences cited therein.

FIELD OF THE INVENTION

This invention relates, in general, to an actuator and sensor assemblyand, more particularly, to a non-contacting linear position sensorcoupled to an actuator.

BACKGROUND OF THE INVENTION

Position sensing is used to electronically monitor the position ormovement of a mechanical component. The position sensor is coupled to anactuator and is adapted to produce an electrical signal that varies asthe position of the component in question varies. Actuator and sensorassemblies are included in many products. For example, actuator andsensor assemblies allow the status of various automotive components tobe monitored and controlled electronically.

A position sensor needs to be accurate, in that it must give anappropriate electrical signal based upon the position measured. Ifinaccurate, a position sensor may hinder the proper evaluation andcontrol of the position of the component being monitored.

Typically, it is also a requirement that a position sensor be adequatelyprecise in its measurement However, the precision needed in measuring aposition will obviously vary depending upon the particular circumstancesof use. For some purposes, only a rough indication of position isnecessary; for instance, an indication of whether a valve is mostly openor mostly closed. In other applications, more precise indication ofposition may be needed.

A position sensor should also be sufficiently durable for theenvironment in which it is placed. For example, a position sensor usedon an automotive valve may experience almost constant movement while theautomobile is in operation. Such a position sensor should be constructedof mechanical and electrical components adequate to allow the sensor toremain sufficiently accurate and precise during its projected lifetime,despite considerable mechanical vibrations and thermal extremes andgradients.

In the past, position sensors were typically of the “contact” variety. Acontacting position sensor requires physical contact to produce theelectrical signal. Contacting position sensors typically consist ofpotentiometers that produce electrical signals which vary as a functionof the component's position. Contacting position sensors are generallyaccurate and precise. Unfortunately, the wear due to contact duringmovement has limited their durability. Also the friction resulting fromthe contact can degrade the operation of the component Further, waterintrusion into a potentiometric sensor can disable the sensor.

One advancement in sensor technology has been the development ofnon-contacting position sensors. A non-contacting position sensor(“NPS”) does not require physical contact between the signal generatorand the sensing element. Instead, an NPS utilizes one or more magnets togenerate magnetic fields that vary as a function of position, anddevices to detect varying magnetic fields to measure the position of thecomponent to be monitored. Often, a Hall Effect device is used toproduce an electrical signal that is dependent upon the magnitude,polarity, or direction of the magnetic flux incident upon the device.The Hall Effect device may be physically attached to the component to bemonitored and thus moves relative to the stationary magnet(s) as thecomponent moves. Conversely, the Hall Effect device may be stationarywith the magnet(s) affixed directly or indirectly to the component to bemonitored. In either case, the position of the component to be monitoredcan be determined by the electrical signal produced by the Hall Effectdevice.

Although currently available actuator and NPS assemblies have provensatisfactory, there continues to be a need for improved, lower costactuator and NPS assemblies.

SUMMARY OF THE INVENTION

The present invention is directed to, in one embodiment, an actuator andsensor assembly which comprises a sensor housing including a walldefining a pocket and a connector assembly which includes a sensor andis adapted for coupling to the sensor housing in a relationship whereinthe sensor extends into the pocket defined by the wall of the sensorhousing. The assembly further comprises an actuator housing including abase defining an aperture and the sensor housing and the actuatorhousing are coupled together and define an interior cavity. A piston islocated and movable in the interior cavity and defines a receptacle. Amagnet is located in the receptacle of the piston and the magnetgenerates a magnetic field. The sensor is adapted to sense a change inthe magnetic field in response to the movement of the piston and themagnet relative to the sensor. The assembly still further comprises anactuator shaft including a first end coupled to the piston and a secondend extending through the aperture in the actuator housing and intocoupling relationship with a movable object.

The actuator and sensor assembly further comprises, in one embodiment, aflexible diaphragm located in the interior cavity and the piston isseated on the flexible diaphragm. A spring is also located in theinterior cavity against the piston and biases the piston in a firstposition. A source of pressurization is coupled to one of the sensorhousing or the actuator housing and in fluid flow communication with theinterior cavity for adjusting the pressure in the interior cavity andcausing the movement of the piston.

The actuator and sensor assembly still further comprises, in oneembodiment, a plurality of clips on one of the sensor housing or theactuator housing and a flange on the other of the sensor housing or theactuator housing. The plurality of clips engage against the flange forcoupling the sensor housing and the actuator housing together.

Further, in one embodiment the magnet comprises at least first andsecond stacked portions made of different magnetic materials. In oneembodiment, the first portion is made of an NdFeB material and thesecond portion is made of either an iron or steel material.

Still further, in one embodiment, the base of the actuator housingdefines a plurality of cavities and the actuator and sensor assemblyfurther comprises a plurality of mounting pins including respectiveheads extending into the plurality of cavities respectively in the baseof the actuator housing. In one embodiment, the base of the actuatorhousing also defines a central cavity, a gimbal is located in thecentral cavity and defines a central through aperture, and the actuatorshaft extends through the central aperture of the gimbal.

Other advantages and features of the present invention will be morereadily apparent from the following detailed description of thepreferred embodiment of the invention, the accompanying drawings, andthe appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings that form part of the specification, and inwhich like numerals are employed to designate like parts throughout thesame:

FIG. 1 is a perspective view of an actuator and sensor assembly inaccordance with the present invention;

FIG. 2 is a broken vertical cross-sectional view of the actuator andsensor assembly shown in FIG. 1;

FIG. 3 is an exploded perspective view of the actuator and sensorassembly of FIG. 1;

FIG. 4 is a broken perspective view of the sensor housing and theconnector assembly of the actuator and sensor assembly of FIGS. 1-3;

FIG. 5 is a vertical cross-sectional view of the connector assembly, thesensor housing, and the piston/magnet carrier assembly of the actuatorand sensor assembly shown in FIGS. 1-3;

FIG. 6 is a top perspective view of the of the piston/magnet carderassembly seated in the diaphragm of the actuator and sensor assemblyshown in FIGS. 1-3;

FIG. 7 is a top perspective view of the actuator housing of the actuatorand sensor assembly shown in FIGS. 1-3;

FIG. 8 is a vertical cross-sectional view of the actuator housing of heactuator and sensor assembly shown in FIGS. 1-3;

FIG. 9 is a simplified perspective view of a first alternate embodimentof the magnet assembly of the actuator and sensor assembly shown inFIGS. 1-3;

FIG. 10 is a simplified diagram depicting the magnetic field generatedby the magnet assembly of FIG. 9;

FIG. 11 is a simplified perspective view of a second alternateembodiment of the magnet assembly of the actuator and sensor assemblyshown in FIGS. 1-3; and

FIG. 12 is a simplified perspective view of a third alternate embodimentof the magnet assembly of the actuator and sensor assembly shown inFIGS. 1-3.

DETAILED DESCRIPTION OF THE EMBODIMENT

An actuator and sensor assembly 200 in accordance with the presentinvention is shown in FIGS. 1-3.

Actuator and sensor assembly 200 initially comprises an upper or topsensor housing or cover member 22 (FIGS. 1, 2, 3, 4) and a lower orbottom actuator cover or housing member 210 (FIGS. 1, 2, 3, 7, 8) whichare coupled to each other and together define an interior housing orenclosure or chamber for a plurality of elements including a combinationpiston/magnet carrier assembly 100 (FIGS. 2, 3, 5, 6) and a spring 150(FIGS. 2 and 3) as described in more detail below.

Sensor housing or cover 22, which may be made from any suitableinjection molded plastic, is in the embodiment shown generallydome-shaped and includes a rounded top wall or roof 27 (FIGS. 2, 3, 5)and a unitary downwardly extending circumferential exterior wall orskirt portion 23 (FIGS. 2, 3, 5) having an inner surface 24 and an outersurface 25. The roof 27 and the skirt portion 23 together define aninterior sensor cavity or chamber 26.

The roof 27 further includes a dome 29 (FIGS. 2, 3, 5) defining aninterior bore or cavity 28 that is co-axial with and opens into thecavity 26. The dome 29 further defines an exterior circumferentialrecess 30 (FIGS. 2, 3) and a collar 32 (FIGS. 2, 3) which surrounds therecess 30. An elongate, generally cylindrical hollow tube 31 (FIGS. 1,3, 5) extends generally vertically outwardly and upwardly from a portionof the roof 27 and defines an interior port or passage 33 (FIG. 5) influid flow communication with the interior of the cavity 26. The tube 31can be connected to a source of pneumatic fluid such as air.

A circumferentially extending shoulder or collar 44 a (FIGS. 2 and 5)extends downwardly into the cavity 26 from a portion of the interiorsurface of the roof 27. A circumferential recess or groove 34 is definedin a portion of the interior surface of the roof 27 and surrounds thecollar 44 a.

An elongated circumferentially extending wall 36 (FIGS. 4, 5) extendsunitarily downwardly from another portion of the interior surface of thewall or roof 27 into the cavity 26. The wall 36 includes a first pair ofspaced-apart and generally parallel and vertically oriented side wallportions 36 a and 36 b, a second pair of spaced-apart and generallyparallel and vertically oriented wall portions 36 c (only one of whichis shown in FIG. 4), and a bottom generally horizontal wall or floor 38which connects the lower distal peripheral ends of the vertical wallportions 36 a, 36 b, and 36 c. The wall 36 and, more specifically, wallportions 36 a, 36 b, 36 c, and 36 d thereof together define asensor/substrate cavity or pocket 40 (FIG. 5) which is accessiblethrough an opening 41 (FIG. 5) defined in the roof 27 of the housingmember 22 by the wall 36. The wail 36 and, more specifically, the wallportions 36 a, 36 b, 36 c, and 36 d thereof separate and isolate thepocket 40 from the cavity 26, i.e., the pocket 40 is defined and boundedby the respective interior surfaces of the respective walls 36 a, 36 b,36 c, and 36 d, while the respective exterior surfaces of the respectivewalls 36 a, 36 b, 36 c, and 36 d face the cavity 26.

A plurality of generally L-shaped flexible elongate clips or fingers 42(FIGS. 2, 3, 5) protrude outwardly from the outside surface of the skirtportion 23 of the housing member 22 thereof. Each of the clips 42includes a distal end 43 (FIGS. 2 and 5) which projects or extendsdownwardly past the distal circumferential edge of the skirt 23 andterminates in an inwardly projecting distal rib or ledge or shoulder 44.

A connector assembly 50 (FIGS. 1, 2, 3, 5), which may also be made fromany suitable injection molded plastic, is mounted over and coupled tothe roof 27 of the housing member 22 and, more specifically, over thedome 29 of the roof 27 of the housing member 22. Connector assembly 50includes a body 51 and a shroud 52 that extends unitarily from the body51 in a relationship spaced from and generally parallel to the roof 27of the housing 22. The shroud 52 defines an open interior 53 (FIG. 5). Alocking tab 54 is located on and projects outwardly from a top exteriorsurface of the shroud 52. An electrical connector (not shown) is adaptedto be coupled to the end of the shroud 52 and retained to the shroud 52by the locking tab 54. The electrical connector (not shown) may beconnected to a wire harness (not shown).

Connector assembly 50 further comprises an annular distalcircumferential flange 56 (FIGS. 2, 3, 5) that extends and projectsgenerally normally and unitarily outwardly from a distal peripheralcircumferential edge of the body 51. The connector assembly 50 iscoupled to and over the top of the housing member 22 and, morespecifically, the walls 27 and 36 of the housing member 22 in arelationship wherein the flange 58 of the connector assembly 50 isseated in the recess 30 of the housing member 22; is surrounded by thecollar 32 of the housing member 22; and is secured to the housing member22 by heat staking, ultrasonically welding, or the like means or method.The body 51 further defines an interior recess 57 (FIG. 5) which allowsthe connector assembly 50 to be seated over the dome 29 defined by thewall/root 27 of the housing member 22. The body 51 of connector assembly50 also includes a downwardly projecting unitary arm 58 that extendsthrough the opening 41 in the wall 36 and partially into the pocket 40defined by the wall 36 of the housing member 22 when the connectorassembly 50 is seated on and coupled to the top of the housing member22.

A plurality of electrically conductive generally L-shaped terminals 84(only one of which is shown in FIG. 5) are insert-molded into and extendthrough the body 51 of the connector assembly 50. The terminals 84 areretained by, and pass through, the interior of the body 51 and onto thearm 58. Each of the terminals 84 defines respective opposed distal ends85 and 86. The terminal end 85 extends into the interior cavity 53defined by the shroud 52 and is adapted for connection to an electricalconnector (not shown). The terminal end 86 extends over the distal endof the arm 58 and is coupled to a substrate 80 (FIG. 5) bypress-fitting, soldering, wire-bonding, or the like means or method.

Substrate 80 can be a conventional printed circuit board formed from FR4or the like material. The substrate 80 extends generally co-planarlyoutwardly from the distal end of the arm 58 in a relationship generallynormal to the shroud 52. A sensor 82 (FIG. 5) is mounted to one of theexterior surfaces of the substrate 80. Sensor 82 can be a magnetic fieldsensor such as a Hall Effect device. In one embodiment, the sensor 82 isan integrated circuit available from Melexis Corporation of leper,Belgium which is adapted to sense and measure at least changes in thedirection of the magnetic field generated by the magnet.

Although not shown, it is understood that other electronic componentssuch as, for example, capacitors, resistors, inductors and other signalconditioning components are mounted on one or both exterior surfaces ofthe substrate 80. Additionally, it is understood that one or morecircuit lines (not shown) are also located and defined on or in thesubstrate 80 for electrically connecting the sensor 82 and the otherelectronic components thereon to the end 86 of the respective terminals84 on the arm 58 of the connector assembly 50.

As shown in FIG. 5, when the connector assembly 50 is coupled to the topof the roof 27 of the housing cover 22, a portion of the arm 58 thereofand the substrate 80 coupled to the distal end of the arm 58 extend intothe housing pocket 40 which is defined in the roof 27 of the housingmember 22 by the circumferential wall 36 thereof.

The actuator assembly 200 also comprises a lower or bottom actuatorcover or housing member 210 which may also be made from a suitableinjection molded plastic. The housing member 210 includes a generallycircular-shaped bottom wall or floor or base 214 (FIGS. 2, 8) and acircumferential side wall 216 which extends generally unitarily upwardlyfrom a peripheral circumferential edge of the floor 214. The walls 214and 216 together define a cup-shaped housing member 210 which defines aninterior cavity or chamber 212 (FIGS. 2, 3, 7, 8). An upper terminal endportion of the side wall 216 defines a circumferentially extending andoutwardly projecting flange or collar or ledge or lip 218 (FIGS. 2, 3,7, 8). A central through aperture 222 (FIGS. 2, 8) defines an entry intothe cavity or chamber 212 and extends through the floor 214 of thehousing member 210.

A first interior circumferentially extending wall 223 (FIGS. 2, 3, 7, 8)protrudes generally normally unitarily upwardly from a center portion ofthe interior surface of the floor 214 of the housing member 210. Wall223 surrounds and is spaced from the central aperture 222 defined in thefloor 214 of the housing member 210.

The floor 214 and the wall 223 together define a pocket or cavity 225(FIGS. 2, 8) for a gimbal 226 (FIGS. 2, 3, 7, 8). The gimbal 226 definesa central through aperture 227 (FIGS. 3, 7, 8) and an outer surfacedefining a circumferential recess 228 (FIGS. 2, 8) adapted to receive ancaring 229 (FIGS. 2, 3, 8) which provides a flexible mechanical bearingbetween the interior surface of the wall 223 of the housing member 210and the gimbal 226.

The floor 214 of the housing member 210 additionally defines at leastthree generally cylindrically-shaped hollow peripheral heads 230 (FIGS.2, 8) protruding outwardly from the interior surface of the floor 214and defining respective interior cavities. Each of the heads 230 definesan opening and a generally ring-shaped groove or shoulder 230 a (FIGS. 2and 8) in the floor 214 of the housing member 210.

Actuator assembly 200 further comprises a plurality of mounting screwsor pins 234 (FIGS. 2, 3, 8) which are insert molded into the respectivecavities in the respective heads 230 defined in the floor 214 of thehousing member 210. Specifically, each of the pins 234 includes a head234 b which is insert molded into the respective head 230 in the floor214 of the housing member 210 and a ring or flange 234 a which surroundsthe head 234 b and extends into abutting relationship with therespective ring-shaped groove 230 a formed in the floor 214 of thehousing member 210.

Each of the pins 234 further includes a leg 234 c (FIGS. 2, 3, 8) whichis adapted to extend through the respective openings of a supportingbracket (not shown) which is fastened to a vehicle engine or enginecomponent such as, for example, a turbocharger.

The respective housing members 22 and 210 are snap-fitted or clippedtogether as shown in FIG. 2. Specifically, and although not shown in anyof the FIGURES, it is understood that when the respective housingmembers 22 and 210 are brought together during the assembly process, theflange 218 on the housing member 210 is brought into abuttingrelationship with the exterior sloped side wall of the respectiveprojections 44 formed on the interior surface of the distal end 43 ofthe respective flexible clips 42 formed on the housing member 22 whichcauses the respective clips 42 to initially flex outwardly and then backinwardly after the flange 218 on the housing member 210 clears therespective projections 44 into the relationship as shown in FIG. 2wherein the lower surface of the flange 218 is seated against the uppersurface of each of the respective projections 44 on the respective clips42 and the terminal distal end of the wall 23 of the housing member 22is disposed opposite and generally co-planarly with, the terminal distalend of the wall 216 of the housing member 210.

Actuator and sensor assembly 200 further comprises a flexible rubberplunger or diaphragm 240 (FIGS. 2, 3, 6) which, as particularly shown inFIG. 2, is located in the cavity 212 of the housing member 210.Diaphragm 240, in the configuration as shown in FIGS. 2, 3, and 6, is inthe shape of a cup having a bottom annular wall or floor or base 242(FIGS. 2, 3, 5, 6) and a peripheral circumferentially extending sidewall 241 (FIGS. 2, 3, 5, 6) including a distal outwardly projecting andcircumferentially extending flange or collar or lip 243 (FIGS. 2, 3, 5,6). The floor 242 also defines a central opening 244 (FIGS. 3, 5). Inthe configuration of FIGS. 2, 3, and 6, the wall 241 and floor 242together define an interior cavity or recess 246 (FIG. 3).

As shown in FIG. 2, the collar or flange 243 of the diaphragm 240 iswedged and secured between the top exterior surface of the flange 218 ofthe housing member 210 and the terminal exterior end surface of the wall23 of the housing member 22 in the coupled and snapped togetherrelationship of the respective housing members 22 and 210.

Actuator and sensor assembly 200 still further comprises a circularpiston washer 336 (FIGS. 2, 3, 5) which defines a central aperture 337(FIGS. 3 and 5). Piston washer 336 is seated in the interior of theassembly 200 against the top exterior surface of the wall 223 of thehousing member 210 in a relationship wherein the central aperture 337thereof is aligned with the central aperture 222 defined in the floor214 of the housing member 210.

Actuator and sensor assembly 200 still further comprises an elongatedpiston rod or actuator shaft 270 (FIGS. 1, 2, 3, 5, 6) including opposedends 272 and 273 (FIGS. 3, 5). Shaft 270 can be attached to a variety ofobjects whose linear position requires adjustment or measurement suchas, for example, the by-pass or waste gate valve of a turbo-charger thatis attached to an engine.

The end 272 of the shaft 270 additionally defines a head 275 (FIGS. 3,5) which abuts against the top collar 136 of a piston insert 133 asdescribed in more detail below. The end 272 of the shaft 270additionally defines a circumferentially and inwardly extending shoulderor recess 271.

A piston rod or shaft adjuster 400 (FIGS. 1, 3) is coupled to the lowerend 273 of the shaft 270. Adjuster 400 defines an aperture 402 (FIG. 3)which receives a ball joint 404 (FIG. 3). Piston/magnet carrier assembly100 (FIGS. 2, 3, 5, 6), which may also be made from any suitableinjection molded plastic, is located in the interior of the assembly 200and, more specifically, in the cavities 26 and 212 of the respectivehousing members 22 and 210 as described in more detail below.Piston/magnet carrier assembly 100 is generally cup-shaped and includesa circular circumferentially extending annular base 102 and acircumferential side wall 110 which extends unitarily generally normallyupwardly from the peripheral circumferential edge of the base 102. Thebase 102 has a top portion or face 104 and a bottom portion or face 106.

Piston/magnet carrier assembly 100 further includes a hollow tube orreceptacle 120 (FIGS. 2, 3, 5, 6) which, in the embodiment shown, isgenerally cylindrically shaped and extends centrally unitarily upwardlyfrom the top portion 104 of the base 102 in a relationship generallynormal to the base 102. The tube 120 is defined by a circumferentialcylindrical wall defining an interior cylindrical surface 124. The tube120 and, more specifically, the interior surface 124 thereof, defines anelongate magnet receiving bore or pocket or receptacle that, in turn,defines central through openings 127 and 129 (FIG. 5) in the top of thetube 120 and the base 102 of the piston/magnet carrier assembly 100respectively. The interior surface 124 of the tube 120 also defines acircumferential recess or groove 131 (FIG. 5) located adjacent butspaced from the base 102, The base 102 and, more specifically, thebottom face 106 thereof, defines a central annular recess or groove 132(FIG. 5) which surrounds the central opening 129 and is spaced from andparallel to the recess or groove 131 defined in the tube 120.

The piston insert 133 (FIGS. 2, 3, 5) is fitted in the interior of thetube 120. Insert 133 comprises a cylindrical hollow neck 134 (FIGS. 2,3, 5) including opposed distal ends terminating in respective annularcollars 135 and 136 projecting outwardly from the outer surface of theneck 134. Collar 135 is wider than the collar 136.

During the assembly process, the insert 133 is fitted by insert-moldingor other means in the lower end of the tube 120 into a relationshipwherein the outside surface of the neck 134 of the insert 133 ispositioned in abutting relationship with and against the interiorsurface 124 of the tube 120 and the respective collars 135 and 136 arefitted into the respective recesses or grooves 132 and 131 in the tube120 and the base 102 of the piston/magnet carrier assembly 100respectively.

Still further, during the assembly process, the diaphragm 240 is wrappedaround the exterior of the piston/magnet carrier assembly 100 as shownin FIGS. 2 and 6 (i.e., the piston/magnet carrier assembly 100 is seatedin and against the diaphragm 240). The washer 336 is then abuttedagainst the exterior surface of the diaphragm 240 in a relationshipwherein the central aperture 337 thereof is positioned co-linearly withthe central aperture 244 of the diaphragm. Also, during the assemblyprocess, the shaft 270 and, more specifically, the end 272 thereof, isthen inserted and extended successively through the apertures 337 and244 in the washer 336 and the diaphragm 240 respectively and thenthrough the interior of the piston insert 133 into a relationshipwherein the circumferential shoulder 271 extending around the end 272 ofthe shaft 270 is abutted against the exterior surface of the washer 336and the distal end face of the end 272 of the shaft 270 protrudesoutwardly from and past the collar 136 of the piston insert 133.Further, during the assembly process, the head 275 of the shaft 270 isthen formed on the distal end face of the end 272 of the shaft 270, asby welding or the like method, through the open top of the tube 120 tosecure the end 272 of the shaft 270, and thus the shaft 270, to thepiston/magnet carrier assembly 100.

Also, during the assembly process, an elongated magnet 140 (FIGS. 2, 3,5) is inserted into the interior of the tube 120 of the piston/magnetcarrier assembly 100 through the top of the tube 120 and is held inplace therein with a heat stake 112 (FIGS. 5 and 6) which is formed atthe top end of the tube 120. Alternatively, the magnet 140 may be pressfit into the tube 120.

Magnet 140 is a permanent magnet that is polarized to define a northpole and a south pole (FIGS. 2, 5). Magnet 140 can, in one embodiment,be made from any one of several different magnetic materials such as,but not limited to, ferrite or samarium cobalt or neodymium-iron-boron.Magnet 140 can be cylindrical in shape as shown or may be of any otherdesired shape or configuration such as, for example, square and thus itis also further understood that the tube 120 may also be shaped andconfigured to accept or house any other differently shaped or configuredmagnet such as, for example, a square shaped tube to accept or house asquare shaped magnet.

Thereafter, and still during the assembly process, the piston/magnetcarrier assembly 100 with the diaphragm 240 and the shaft 270 coupledthereto is mounted in the interior of the cavity 212 of the housingmember 210 into the relationship as shown in FIG. 2 wherein thepiston/magnet carrier assembly 100 is seated against the top of the wail223 of the housing member 210 and the shaft 220 extends successivelythrough the openings 227 and 222 defined in the gimbal 226 and the base214 of the housing member 210 respectively.

The assembly 200 still further comprises a helical metal coil spring 150(FIGS. 2, 3) which is also located in the interior of the assembly 200and, more specifically, is located and mounted in the region of theinterior cavity 26 bounded by the interior surface of the roof 27 of thehousing member 22 at one end and the base 102 of the piston/magnetcarrier assembly 100 at the other end. Coil spring 150 has opposed ends152 and 154 (FIG. 2). End 152 is seated in and against the groove 34defined in the interior surface of the roof 27 of the housing member 22and the end 154 is seated against the top surface 104 of the base 102 ofthe piston/magnet carrier assembly 100. Spring 150 surrounds and isspaced from the tube 120. Although not shown in any of the FIGURES,spring 150 also extends around and is spaced from the wall 36 and thesensor pocket 40. The pocket 40 is thus located between the magnetcarrier tube 120 and the spring 150.

The spring 150 biases and keeps the piston/magnet carrier assembly 100in a first position as shown in FIG. 2 against the top of the wall 223of the housing member 210 and is oriented such that the spring 150 canbe compressed and depressed along the axis of movement of piston/magnetcarrier assembly 100.

Although not shown or described in great detail herein, it is understoodthat the tube 31 is connected to a source of vacuum such as an engineintake manifold or vacuum tank (not shown). An increase in the vacuum inthe tube 31 causes a decrease in the air pressure in the interior of theassembly 200 and causes the piston/magnet assembly 100 to move linearlyupwardly from its first position as shown in FIG. 2 to a plurality ofintermediate linear positions in the interior of the assembly 200including, for example, the second position as shown in FIG. 5 whereinthe piston/magnet carrier assembly 100 is located entirely in theinterior chamber 26 defined by the housing member 22 and the tube 120 isat least partially extended into the interior cavity 28 defined by thedome 29 of the housing member 22. In this second position, the spring150, which is shown in broken form in FIG. 5 for simplificationpurposes, is compressed.

A decrease in the vacuum in the tube 31 and thus an increase in the airpressure in the interior of the assembly 200 and, more specifically, theinterior cavities 26 and 212 defined by the respective housing members22 and 210, causes the piston/magnet carrier assembly 100 to movelinearly downwardly in the chamber or cavity 212 from its secondposition as shown in FIG. 5 back to its biased first position of FIG. 2wherein the plate 336 coupled to the bottom of the piston/magnet carrierassembly 100 is abutted against the top of the wall 223 of the housingmember 210 and the spring 150 is in its fully extended position.

Piston/magnet carrier assembly 100 thus is capable of moving linearly inthe interior of the assembly 200 with respect to the Hall Effect sensor82 which is located inside the pocket 40 in a generally opposed,adjacent, and isolated relationship relative to the magnet 140. Thesensor 82 is spaced, separated, and isolated from the magnet 140 by thepocket wall 36. The magnetic field produced by the magnet 140 passesthrough the wall 36 where the magnitude and/or direction of the magneticfield is sensed by the sensor 82. As the magnet 140 moves linearly inthe interior of the assembly 200 relative to the sensor 82, the northand south poles change position relative to the sensor 82 thus creatinga change in the magnitude and/or direction of the magnetic field. Thechanges in the direction and/or magnitude of the magnetic field can besensed about two axes by the sensor 82.

Sensor 82 produces an electrical signal that changes in response to theposition of the magnet 140 and thereby also a change in the position ofthe shaft 270, The electrical signal produced by the sensor 82 isindicative of the position of the magnet 140 and the piston/magnetcarrier assembly 100. As the magnetic field generated by the magnet 140varies with the movement of the shaft 270, the electrical output signalproduced by sensor 82 changes accordingly, allowing the position of theshaft 270 and thus the object coupled thereto to be determined.

Further, and as shown in FIG. 5 which depicts the piston/magnet carrierassembly 100 in its fully extended linear position within the cavity 26of the housing member 22, it is understood that the piston/magnetcarrier assembly 100 is also adapted for see-saw, tilting, up and downtype movement in response to a tilting, back and forth movement of theshaft 270 which, in turn, allows for the tilting, side to side movementof the tube 120.

FIGS. 9 and 10 depict a first alternate simplified embodiment of amagnet assembly 1140 which, in accordance with the present invention,can be substituted for the magnet assembly 140 shown in FIGS. 2, 3, and5.

The cost of non-contacting position sensors is dependent in part uponthe cost of each of the constituent parts thereof including the cost ofthe magnet assemblies thereof which, in turn, is dependent upon the costof the material of the magnet 140 which is made entirely from NdFeB(neodymium/iron/boron) or a like high strength magnetic material. NdFeBand other like high strength magnetic materials are, however, relativelyhigh cost materials when compared to, for example, other magneticmaterials such as, for example, iron or steel.

In the magnet assembly 1140, one or more of the portions thereof hasbeen substituted with one or more pole pieces or portions composed ofiron or steel or another like low cost ferromagnetic material asdiscussed in more detail below.

More specifically, in FIGS. 9 and 10, the magnet assembly 1140 is in theform of an elongated cylinder and comprises a centralcylindrically-shaped magnet portion 1120 made of NdFeB or the like highstrength magnetic material and opposed cylindrically-shaped end polepieces or portions 1122 and 1124 which have been coupled and stackedonto the respective opposed ends of the central portion 1120 and arecomprised of any suitable lower cost ferromagnetic material capable ofconducting and directing magnetic fields such as, for example, iron orsteel. In the embodiment shown, pole pieces 1122 and 1124 are equal inlength to each other but shorter in length than the central magnetportion 1120.

As shown in FIG. 10, the magnet assembly 1140 of FIG. 9 allows thegeneration of a magnetic flux field 1116 which extends internallythrough the interior of both the central NdFeB magnet portion 1120 andthe two end pole pieces or portions 1122 and 1124 and then externally ina generally radial pattern which extends and travels through the Halleffect sensor 82 which, as described earlier above, is adapted to senseat least the direction/polarity/phase angle of the magnetic flux 1116 toproduce an electrical signal which is dependent upon thepolarity/direction/phase angle of the magnetic flux field 1116.

Thus, the use of end pole pieces or portions 1122 and 1124 made of a lowcost magnetic material advantageously increases the effective length ofthe magnet 1140 and thus the effective path and strength of the magneticflux field 1116 both internally and externally of the magnet assembly1140 in a package which is lower in cost than currently available magnetassemblies.

FIG. 11 depicts a second alternate embodiment of a magnet assembly 2140which comprises a central elongated, generally cylindrically-shaped polepiece or portion 2130 made of any suitable ferromagnetic material suchas, for example, iron or steel and two end magnet pieces or portions2132 and 2134 which have been coupled and stacked onto opposed distalends of the central pole piece 2130 and are each made of NdFeB or thelike high strength magnetic material. In the embodiment shown, each ofthe end magnet pieces or portions 2132 and 2134 has the same length buthas a length which is less than about one half the length of the centralpole piece or portion 2130.

FIG. 12 depicts yet another alternate embodiment of a magnet assembly3140 which comprises two elongate generally cylindrical portions whichhave been coupled and stacked together end over end, i.e., a magnetportion 3240 made of NdFeB or the like high strength magnetic materialand a pole piece or portion 3243 made of any suitable lower costferro-magnetic material such as iron or steel. In the embodiment shown,each of the portions 3240 and 3243 has the same length.

Although not described in detail herein, it is understood that themagnet assemblies 2140 and 3140 are adapted to be displaced linearly inthe same up and down direction generally designated Y in FIGS. 11 and 12and generate magnetic flux fields similar to the magnetic flux field1116 generated by the magnet assembly 1140 for sensing by the Halleffect sensor 82 (FIGS. 11 and 12) which is positioned in a spaced andparallel relationship to the respective magnet assemblies 2140 and 3140.

Thus, and as described above, the present invention is also directed toan actuator and sensor assembly 200 adapted to use different magnetassembly embodiments, which may be of any desired shape andconfiguration including cylindrical or square, in which one or more ofthe magnet portions thereof made of NdFeB or the like high strength buthigh cost magnetic material have been substituted with one or morerespective pole pieces or portions made of a ferromagnetic material suchas iron or steel to reduce the overall cost of the magnet assemblywithout, however, affecting the overall effective length of the magnet,the strength of the magnetic field generated by the magnet assembly, orthe performance of the magnet assembly.

While the invention has been taught with specific reference to theembodiment shown, it is understood that a person of ordinary skill inthe art will recognize that changes can be made in form and detailwithout departing from the spirit and the scope of the invention, Thedescribed embodiment is to be considered in all respects only asillustrative and not restrictive.

What is claimed is:
 1. An actuator and sensor assembly comprising: asensor housing including a wail defining a pocket; a connector assemblyincluding a sensor, the connector assembly being adapted for coupling tothe sensor housing in a relationship wherein the sensor extends into thepocket defined by the wall of the sensor housing; an actuator housingincluding a base defining an aperture, the sensor housing and theactuator housing being coupled together and defining an interior cavity;a piston located and movable in the interior cavity and defining areceptacle; a magnet located in the receptacle of the piston, the magnetgenerating a magnetic field, the sensor being adapted to sense a changein the magnetic field in response to movement of the piston and themagnet relative to the sensor; and an actuator shaft including a firstend coupled to the piston and a second end extending through theaperture in the actuator housing and into coupling relationship with amovable object.
 2. The actuator and sensor assembly of claim 1 furthercomprising: a flexible diaphragm located in the interior cavity, thepiston being seated on the flexible diaphragm; a spring located in theinterior cavity against the piston and biasing e piston in a firstposition; and a source of pressurization coupled to one of the sensorhousing or the actuator housing and in fluid flow communication with theinterior cavity for adjusting the pressure in the interior cavity andcausing the movement of the piston.
 3. The actuator and sensor assemblyof claim 1 further comprising a plurality of clips on one of the sensorhousing or the actuator housing and a flange on the other of the sensorhousing or the actuator housing, the plurality of clips engaging againstthe flange for coupling the sensor housing and the actuator housingtogether.
 4. The actuator and sensor assembly of claim 1 wherein themagnet comprises at least first and second stacked portions made ofdifferent magnetic materials.
 5. The actuator and sensor assembly ofclaim 4 wherein the first portion is made of an NdFeB material and thesecond portion is made of either an iron or steel material.
 6. Theactuator and sensor assembly of claim 1 wherein the base of the actuatorhousing defines a plurality of cavities, the actuator and sensorassembly further comprising a plurality of mounting pins includingrespective heads extending into the plurality of cavities respectivelyin the base of the actuator housing.
 7. The actuator and sensor assemblyof claim 1 wherein the base of the actuator housing defines a centralcavity, the actuator and sensor assembly further comprising a gimballocated in the central cavity and defining a central through aperture,the actuator shaft extending through the central aperture of the gimbal.8. A sensor assembly comprising: a sensor housing including a walldefining an opening and a pocket; a connector including a sensor, theconnector being coupled to the sensor housing in a relationship whereinthe sensor extends through the opening and into the pocket defined bythe wall of the sensor housing; and a magnet located adjacent the pocketand adapted for movement relative to the sensor in the pocket, thesensor being adapted to sense a change in the magnetic field generatedby the magnet in response to the movement of the magnet relative to thesensor.
 9. The sensor assembly of claim 8 wherein the connector includesa plurality of terminals coupled to a substrate, the sensor beingmounted on the substrate and the substrate extending into the pocketdefined by the wall of the sensor housing.
 10. A sensor assemblycomprising: a sensor housing including a wall defining an opening and apocket; a connector including a sensor, the connector being coupled tothe sensor housing in a relationship wherein the sensor extends throughthe opening and into the pocket defined by the wall of the sensorhousing; a magnet located adjacent the pocket and adapted for movementrelative to the sensor in the pocket, the sensor being adapted to sensea change in the magnetic field generated by the magnet in response tothe movement of the magnet relative to the sensor; an actuator housingincluding a base defining an aperture, the actuator housing beingcoupled to the sensor housing and together defining an interior chamber;a piston located in the interior chamber, the piston defining a carrierfor the magnet: a flexible diaphragm located in the interior chamber andincluding a peripheral edge wedged between the sensor housing and theactuator housing, the piston being seated against the flexiblediaphragm; an actuator shaft including a first end coupled to the pistonand an opposite end extending through the aperture in the base of theactuator housing and into coupling relationship with a movable object;and a source of pressurization coupled to the sensor housing or theactuator housing and in communication with the interior chamber foradjusting the pressure in the interior chamber and causing the movementof the piston, the magnet thereon, the actuator shaft, and the movableobject coupled thereto.
 11. The sensor assembly of claim 10 furthercomprising: a hollow insert in the piston, the actuator shaft extendingthrough the insert and the actuator shaft including a head seatedagainst the top of the insert; a first central cavity and a plurality ofsecond peripheral cavities defined in the base of the actuator housing;a hollow gimbal located in the first central cavity, the actuator shaftextending through the gimbal; and a plurality of mounting pins includingrespective heads extending into the respective second peripheralcavities defined in the base of the actuator housing.
 12. The sensorassembly of claim 8 wherein the magnet comprises at least first andsecond stacked portions made of different magnetic materials.